1. Field of the Disclosure
The disclosure relates to a highly loaded pearlescent pigment acrylic polymer slurry concentrate for use as a pearlescent pigment additive for an acrylic polymer sheet, in particular the disclosure relates to an acrylic monomer pearlescent pigment slurry which comprises a copolymer dispersant.
2. Description of the Related Art
Acrylic sheets for making cast acrylic articles such as flooring, spas and ornamental products can be prepared from a curable acrylic solution comprising a monomer/copolymer mixture together with additives and pigments, including pearlescent pigments. A cast acrylic sheet which includes mica particulates is described in WO 03/061937. One particular mica pigment described therein is the Iriodin line of pigments which is included in the acrylic polymer in minor additive amounts with one example including a white pigment masterbatch dispersion together with the pearlescent mica pigment.
Typically, when making pearlescent acrylic sheets, it can be difficult to uniformly disperse the dry pearlescent pigment into the acrylic. While pigments can usually be incorporated by way of a masterbatch, masterbatch production of pearlescent pigments can pose challenges because the pigments tend to settle and form agglomerates which can pose filtration and viscosity problems. Energy intensive milling, which can be used to solve such problems with non-pearlescent pigment masterbatch compositions, can degrade the pearlescent appearance of pearlescent pigments. Consequently, pearlescent pigments are added in a dry powder form to the polymer, but dry addition can pose handling problems.